A significant challenge in the modern datacenter is to ensure that enough resources, such as computer servers, are available to each application or application component in the data center when there is a sudden peak in demand for the application. The problem becomes compounded for aggregate application, which are deployed on a multi-tier architecture, requiring one or more servers for each tier. For example, an aggregate application may include one or more Web servers for clients of the application to connect to, a set of applications servers that implement the business logic of the application, and one or more database servers to manipulate the data required by the application. Enough resources must be provided at each tier to meet the performance goals of the aggregate application.
Multiple application components may also be consolidated on a shared resource. This makes it possible to increase utilization of the shared resource. However, application components may be allocated a larger percentage of the shared resource than needed in order to meet peak demand requirements.